300.000+ stock photos. Great selection. Categorized nicely. Registration required.

Great photo portal and community with news, interviews and galleries. High qulity stuff here.

Over 3 million images starting from 1$ for Medium size images. Free sign-up.Categorized. Great search engine.

Can't get bigger than Getty Images in this business. I don't think you can imagine picture and don't find it here.

More than 800.000 images starting from 1$ for low resolution images and 2$ for print quality images. Free registration is required. Powerful search engine.

Italian stock agency which offers almost 10.000 images. Registration required. No categories, use search engine.

Cheap means 1$ for small size images (web only). Print-quality images cost 3$ and very high resolution images cost 5$. Nicely categorized, no registration.